1. Field of the Invention
The present invention relates to electrical connector shield cases and methods of making them, more particularly to an electrical connector shield case for covering the insulating housing of a plug or receptacle connector to make shielding contact to the shield member of another connector and a method of making it.
2. Description of the Prior Art
Referring to FIG. 6A there is shown an electrical connector shield case 100' according to the prior art. In FIG. 6B, a base 103' of this shield case is secured to an insulating housing having male contacts 101' through an intermediate plate 102' so that the male contacts can be housed in an enclosure 104' which is integral with the base 103'. In use, the female contact of another connector is inserted into the enclosure 104' so that inner bosses 105' of the enclosure 104' can be brought into shielding contact with a shield member, such as a metal case, of the other connector.
As FIGS. 7A through 7F show, the shield case 100' has been manufactured by pressing a metal sheet 10' having a size corresponding to that of the final product. A shield case element 40' is made by pressing the metal sheet 10' by means of a drawing press consisting of the lower die 20' with a projection 21' having a shape substantially identical with the shape of the enclosure 104' and the upper die 30' with a depression 31' having a shape substantially identical with the shape of the enclosure 104' (FIGS. 7B and 7C). The resulting shield case element 40', with a protruded portion 41' and a flange portion 42' is then pressed in another press consisting of the lower die 50' with a projection 51' having a cross section substantially identical with that of the protruded portion 41' and a depression 52' shaped corresponding to the periphery of the base 103' and the upper die 60' with a depression 61' having a cross section substantially identical with that of the protruded portion 41' and a projection 62' shaped corresponding to the periphery of the base 103' to open the top of the protruded portion 41' and cut the flange portion 42' to a predetermined shape (FIG. 7E). Then, bosses 105' are made by inserting a core die 70' having recesses 71' at positions corresponding to the bosses 105' of the shield case 100' into the protruded portion 41' of the shield case 100' and pressing the work between a pair of outer dies 80' and 90' each having projections 81' or 91' at positions corresponding to the bosses 105' in the direction of an arrow shown in FIG. 7F. This completes the formation of a shield case 100' such as shown in FIG. 6A.
The manufacture of the above prior electrical connector shield case requires the drawing pressing porcess and has the following drawbacks:
(1) The amount of material loss is large, increasing the material cost; PA0 (2) An extensible, soft material must be used, limiting the range of choices in material and failing to give satisfactory elasticity to the bosses of a case; PA0 (3) The extensible, soft material is susceptible to deformation under an external stress; PA0 (4) The thickness of a case wall varies from section to section. PA0 (5) The outward bosses are very difficult to make.